JP6572710B2 - Terminal structure, power storage device and power storage module - Google Patents

Description

  The present invention relates to a terminal structure, a power storage device, and a power storage module.

  A power storage module in which a plurality of power storage devices such as lithium ion batteries are arranged in one direction and these power storage devices are electrically connected is known. In the assembly of such a power storage module, after a plurality of power storage devices are arranged in one direction and restrained by sandwiching these power storage devices by end plates, the terminals of each power storage device are electrically connected by a bus bar. Is done by. The assembled power storage module is subjected to various inspections such as a short circuit inspection as disclosed in Patent Document 1, for example. As one of such inspections, there is an inspection (hereinafter referred to as “contact resistance inspection”) in which the contact resistance between the positive electrode terminal and the negative electrode terminal is acquired after the bus bar is fastened to the terminal. Thereby, the presence or absence of a foreign object when the bus bar is fastened to the terminal is confirmed.

  In the assembled battery module, the upper end surfaces of the positive electrode terminal and the negative electrode terminal are in contact with the bus bar, and the outer peripheral surfaces of the positive electrode terminal and the negative electrode terminal are covered with nuts or the like for fixing the positive electrode terminal and the negative electrode terminal to the case. Therefore, the lead rod of the resistance measuring instrument cannot be brought into direct contact with the positive electrode terminal and the negative electrode terminal. Therefore, in the contact resistance test, the internal resistance of the battery between the positive electrode terminal and the negative electrode terminal is measured (measured value R1) with the AC resistance meter before the bus bar is fastened. Specifically, the resistance is measured by bringing a lead bar of an AC ohm meter into contact with the positive electrode terminal and the negative electrode terminal. Next, after fastening the bus bar, the resistance between the positive terminal and the negative terminal including the bus bar is measured (measured value R2) with an AC resistance meter. Specifically, the contact resistance is measured by bringing a lead bar of an AC ohmmeter into contact with the bus bar fastened to the positive electrode terminal and the negative electrode terminal, respectively. And the contact resistance value of the bus-bar fastening part of a positive electrode terminal or a negative electrode terminal is acquired by subtracting measurement value R1 from measurement value R2.

Japanese Patent Laying-Open No. 2015-95312

  However, in the conventional contact resistance test, it is necessary to perform measurement twice before and after the bus bar is fastened, resulting in poor workability. In addition, the internal resistance of the battery can be measured only with an AC ohm meter, but the AC ohm meter is affected by eddy currents caused by surrounding metals, so that the accuracy is inferior compared to the case of using a DC ohm meter.

  Then, this invention aims at providing the terminal structure, the electrical storage apparatus, and electrical storage module which can improve the workability | operativity and test | inspection precision at the time of test | inspecting the contact resistance of the bus-bar fastening part of a positive electrode terminal or a negative electrode terminal. To do.

  The terminal structure of the present invention is a terminal structure in a power storage device including a case that accommodates an electrode, and includes a side surface portion of a case having a communication hole that communicates the inside and the outside of the case, and A terminal member that extends between the inside and the outside and is electrically connected to the electrode; and a fixing member that is attached to the outer peripheral surface of the terminal member outside the case and fixes the terminal member to one side surface portion, The fixing member is formed with an inspection hole that communicates from an opening formed on a surface forming the outer shape of the fixing member to an outer peripheral surface of the terminal member.

  In the terminal structure having this configuration, an inspection hole for accessing the outer peripheral surface of the terminal member is formed in the fixing member attached to the outer peripheral surface of the terminal member. That is, even when the power storage device having the terminal structure with the above configuration is assembled as the power storage module, an access path to the terminal member is secured without removing the connection member such as the bus bar. As a result, it is possible to measure the contact resistance between the positive electrode terminal and the negative electrode terminal by directly contacting the lead bar of the ohmmeter via the inspection hole to the positive electrode terminal and the negative electrode terminal. The measurement of the contact resistance between the positive electrode terminal and the negative electrode terminal performed in step 1 can be omitted. In addition, since the lead bar of the ohmmeter can be brought into direct contact with the positive electrode terminal and the negative electrode terminal, a DC ohmmeter can be used instead of an AC ohmmeter. As a result, workability and inspection accuracy when inspecting the contact resistance of the bus bar fastening portion of the positive electrode terminal or the negative electrode terminal can be improved.

  In the terminal structure of the present invention, the terminal member may extend in a direction orthogonal to the direction in which the terminal member extends. According to the terminal structure having this configuration, the lead rod of the ohmmeter inserted into the inspection hole can be easily orthogonal to the terminal member. Thereby, the inspection accuracy can be further improved.

  In the terminal structure of the present invention, a plurality of inspection holes may be formed. According to this terminal structure, since there are more inspection hole options for inserting the lead bar of the ohmmeter, it is possible to reduce the probability of occurrence of an event in which the lead bar cannot be inserted when assembled as a battery module. it can.

  In the terminal structure of the present invention, the inner peripheral surface of the inspection hole may be covered with an insulating material. According to this terminal structure, even when the lead bar of the ohmmeter contacts the inner peripheral surface of the inspection hole, the contact resistance can be accurately measured.

  In the terminal structure of the present invention, the fixing member may be a nut, and the nut may be formed on the outer peripheral surface of the terminal member so as to be screwed into the screw groove. According to this terminal structure, the terminal member can be easily fixed to one side surface portion of the case.

  The power storage device of the present invention includes a case that accommodates a positive electrode and a negative electrode, and a positive electrode terminal and a negative electrode terminal that have the above terminal structure. In the power storage module having this configuration, it is possible to improve workability and inspection accuracy when inspecting the contact resistance of the bus bar fastening portion of the positive terminal or the negative terminal.

According to the battery device of the present invention, when the direction in which the positive electrode terminal and the negative electrode terminal are opposite to each other with the first direction, the inspection hole extends along a first direction, one of the positive terminal and the negative electrode terminal opening in the inspection hole to be formed, may be formed on the side opposite to the side where the other of the positive terminal and the negative electrode terminals are arranged.

  In the power storage device of this configuration, the lead rod of the ohmmeter is not inserted into the inspection hole from between the positive electrode terminal and the negative electrode terminal, and the lead rod is always inserted from the outer side to the inner side of the power storage device. Become. Thereby, workability | operativity at the time of test | inspecting the contact resistance of the bus-bar fastening part of a positive electrode terminal or a negative electrode terminal can be improved more.

  A power storage module of the present invention includes a case that accommodates a positive electrode and a negative electrode, a positive electrode terminal and a negative electrode terminal having the terminal structure, and a plurality of power storage devices, and terminal members of the plurality of power storage devices It is electrically connected by a bus bar.

  In the power storage module having this configuration, an inspection hole for accessing the outer peripheral surface of the terminal member is formed in the fixing member attached to the outer peripheral surface of the terminal member. That is, even when the power storage device is assembled as a power storage module, the access path to the terminal member is secured without removing the bus bar. As a result, it is possible to measure the contact resistance of the bus bar fastening portion of the positive terminal or the negative terminal by directly contacting the lead bar of the ohmmeter directly to the positive terminal or the negative terminal through the inspection hole. The measurement of the internal resistance of the battery between the positive electrode terminal and the negative electrode terminal, which has been performed before assembling, can be omitted. Further, since the lead rod of the ohmmeter can be brought into direct contact with the positive electrode terminal and the negative electrode terminal, not only the AC ohmmeter but also a DC ohmmeter can be used. As a result, workability and inspection accuracy when inspecting the contact resistance of the bus bar fastening portion of the positive electrode terminal or the negative electrode terminal can be improved.

Multiple storage modules of the present invention, when the direction in which the positive electrode terminal and the negative electrode terminal are opposite to each other and to the first direction, the opening of the inspection hole formed in each of the plurality of power storage modules, arranged in one direction All of the power storage devices may be arranged so as to be visible when viewed from the first direction.

  In the power storage module with this configuration, the lead bar of the ohmmeter is not inserted into the inspection hole from between the positive electrode terminal and the negative electrode terminal, and the lead bar is always inserted from the outer side to the inner side of the power storage device. Become. Thereby, workability | operativity at the time of test | inspecting the contact resistance of the bus-bar fastening part of a positive electrode terminal or a negative electrode terminal can be improved more.

  ADVANTAGE OF THE INVENTION According to this invention, workability | operativity and test | inspection precision at the time of test | inspecting the contact resistance of the positive electrode terminal and negative electrode terminal after a bus-bar fastening can be improved.

It is a perspective view showing a battery module provided with a battery cell concerning one embodiment. It is sectional drawing of the battery cell which concerns on one Embodiment. It is sectional drawing which expanded and showed the vicinity of the positive electrode terminal shown in FIG. It is the perspective view which showed the test | inspection hole of the nut shown in FIG. It is sectional drawing which expanded and showed the vicinity of the negative electrode terminal shown in FIG. It is the side view which looked at the battery module of Drawing 1 from the 1st direction.

  Hereinafter, an embodiment will be described with reference to the drawings. In the description of the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted. The dimensional ratios in the drawings do not necessarily match those described. In the description, terms indicating directions such as “up” and “down” are convenient terms based on the state shown in the drawings.

  As shown in FIG. 1, the battery module (power storage module) 1 has a plurality of battery cells (power storage devices) 10 arranged in one direction (array direction D). The plurality of battery cells 10 are integrated by the restraint 3. The restraining tool 3 is, for example, a pair of end plates 3A that sandwich a plurality of battery cells 10 from the juxtaposed direction, and a rod-shaped connecting member that is disposed on the side of the battery cells 10 and connects the pair of end plates 3A, 3A. 3B and a bolt 3C that fixes the connecting member 3B to the end plate 3A in a state where the plurality of battery cells 10 are sandwiched between the end plates 3A. A restraining load is applied to the plurality of battery cells 10 by the restraining tool 3.

  In the plurality of battery cells 10, a negative electrode terminal 70 of one battery cell 10 of adjacent battery cells 10 and 10 and a positive electrode terminal 50 of the other battery cell 10 are connected by a bus bar 5. The arrangement direction of the plurality of battery cells 10 is a direction substantially orthogonal to a straight line connecting the axes of the positive electrode terminal 50 and the negative electrode terminal 70 arranged in one case 11. In other words, the positive electrode terminal 50 and the negative electrode terminal 70 are substantially perpendicular to the direction (first direction) facing each other. Between the battery cells 10, while preventing that the battery cells 10 short-circuit, members (not shown), such as a heat sink, may be provided for heat dissipation.

  As shown in FIG. 2, the battery cell 10 includes a case 11 and an electrode assembly 20. The case 11 is a substantially rectangular parallelepiped casing, for example, and is formed of a metal such as aluminum.

  The electrode assembly 20 is accommodated in the case 11. The electrode assembly 20 includes a plurality of positive electrodes 30 and a plurality of negative electrodes 40, and a plurality of separators disposed between the positive electrodes 30 and the negative electrodes 40. The positive electrode 30 and the negative electrode 40 are alternately stacked along a predetermined direction (the depth direction in FIG. 2) via a separator. The separator is a microporous film, for example, and holds the electrolytic solution between the positive electrode 30 and the negative electrode 40. The electrolytic solution is, for example, an organic solvent-based or non-aqueous electrolytic solution.

  The positive electrode 30 includes, for example, a metal foil such as an aluminum foil, and a positive electrode active material layer provided on both surfaces of the metal foil. The positive electrode active material layer includes, for example, a positive electrode active material and a binder. Examples of the positive electrode active material include composite oxide, metallic lithium, and sulfur. The composite oxide includes, for example, at least one of manganese, nickel, cobalt, and aluminum and lithium. The positive electrode 30 has a tab 33 formed on the upper edge. The tab 33 does not carry a positive electrode active material, and the positive electrode 30 is electrically connected to the conductive member 34 via the tab 33.

  The negative electrode 40 includes, for example, a metal foil such as a copper foil, and a negative electrode active material layer provided on both surfaces of the metal foil. The negative electrode active material layer includes, for example, a negative electrode active material and a binder. Examples of the negative electrode active material include carbon such as graphite, highly oriented graphite, mesocarbon microbeads, hard carbon, and soft carbon, alkali metals such as lithium and sodium, metal compounds, and SiOx (0.5 ≦ x ≦ 1). .5), and boron-added carbon. The negative electrode 40 has a tab 43 formed on the upper edge. The tab 43 does not carry a negative electrode active material, and the negative electrode 40 is electrically connected to the conductive member 44 via the tab 43.

  Next, the terminal structure of the positive electrode terminal 50 and the negative electrode terminal 70 will be described. First, the terminal structure of the positive electrode terminal 50 will be described. As shown in FIG. 3, the positive terminal 50 includes a lid member (one side portion of the case) 12, a terminal member 51, a nut 60, a first insulating portion 65, a second insulating portion 67, and a sealing member. Part 69.

  The lid member 12 is a plate-like member that constitutes one side surface portion of the case 11. The lid member 12 constitutes, for example, the upper surface of the case 11 and functions as a lid for the case 11. Similarly to the case 11, the lid member 12 is formed of a metal such as aluminum. The lid member 12 is formed in a rectangular shape, for example, so as to correspond to the opening shape of the case 11. For example, the outer edge of the lid member 12 is welded to the case 11 to be joined to the case 11 and hermetically seals the inside of the case 11.

  The lid member 12 has a communication hole 13 that communicates the inside and the outside of the case 11. That is, the communication hole 13 penetrates from the inner surface 12 a to the outer surface 12 b of the lid member 12. The communication hole 13 is formed in a circular shape in a plan view, for example. As will be described later, the communication hole 13 is a hole through which the terminal member 51 electrically connected to the electrode assembly 20 in the case 11 is drawn out of the case 11.

  The terminal member 51 has a protruding portion 53 that protrudes from the inside of the case 11 to the outside in the communication hole 13, and a facing portion 55 that faces the lid member 12 inside the case 11. The terminal member 51 is formed of a metal such as aluminum, for example.

  The protruding portion 53 is formed in a substantially cylindrical shape, and extends through the communication hole 13 from the inside of the case 11 to the outside. A nut 60, which will be described in detail later, is fastened to the outer peripheral surface 53a of the protruding portion 53. A thread groove for fastening the nut 60 is formed in at least a portion of the outer peripheral surface 53a to which the nut 60 is fastened. Further, the upper surface 53b of the protruding portion 53 is formed with a fastening hole 53c to which the bolt 6 for fixing the bus bar 5 described above is fastened. The bus bar 5 is electrically connected to the terminal member 51 by contacting the terminal member 51 on the upper surface 53b.

  The facing portion 55 is formed integrally with the protruding portion 53 and faces the lid member 12 inside the case 11. The facing portion 55 extends, for example, in a flat plate shape along the inner surface 12a. The facing portion 55 is connected to the base end of the protruding portion 53 at the center portion.

  The terminal member 51 is electrically connected to the positive electrode 30. Specifically, a current collecting plate 57 extending from the facing portion 55 is electrically connected to the conductive member 34. As described above, the conductive member 34 is electrically connected to the tab 33 of the positive electrode 30 (see FIG. 2). Thereby, the terminal member 51 is electrically connected to the positive electrode 30 via the conductive member 34.

  The nut 60 fixes the terminal member 51 to the lid member 12. The nut 60 is attached to the protruding portion 53 outside the case 11. Specifically, the nut 60 is fixed to the lid member 12 of the case 11 by being screwed into a screw groove formed on the outer peripheral surface 53 a of the protruding portion 53 described above. The nut 60 is formed of, for example, a metal such as stainless steel. Further, the nut 60 is formed with an inspection hole 61 that communicates from an opening 61 a formed on the surface forming the outer shape of the nut 60 to the outer peripheral surface 53 a of the protruding portion 53 of the terminal member 51.

  The inspection hole 61 extends in a direction orthogonal to the direction in which the terminal member 51 (projecting portion 53) extends and parallel to the surface direction of the lid member 12. As shown in FIG. 4, the inspection hole 61 has a circular cross-sectional shape orthogonal to the extending direction, and has a radius of, for example, 1.7 mm to 2.0 mm. Moreover, the length from the opening part 61a in the extending direction to the outer peripheral surface 53a of the protrusion part 53 is 3.0 mm-5.0 mm, for example. The inspection hole 61 can be formed, for example, by drilling a hexagon nut.

  The inspection hole 61 is formed on one of the terminal member 51 of the positive electrode terminal 50 and the terminal member 51 of the negative electrode terminal 70. The opening 61a in the inspection hole 61 is on the side where the other of the positive electrode terminal 50 and the negative electrode terminal 70 is disposed. It is formed on the opposite side. Specifically, as shown in FIG. 6, the opening 61 a of the inspection hole 61 formed in each of the plurality of battery cells 10 includes a plurality of battery cells 10 arranged in one direction, and a positive electrode terminal 50. They are all disposed so as to be visible when viewed from the direction (first direction) in which the negative electrode terminal 70 faces each other. In other words, all the inspection holes 61 are open in the same direction.

  In the case of such a configuration, for example, it is preferable to make the relationship between the screwing start position of the nut 60 with respect to the thread groove formed on the outer peripheral surface of the terminal member 51 and the position of the opening 61a constant. Thereby, the opening 61a of the inspection hole 61 can be directed in the same direction while the tightening torque of the nut 60 is substantially constant.

  A coating layer 63 formed of insulating polyacetal, ultrahigh molecular weight polyethylene, or polyethylene terephthalate is formed on the inner peripheral surface of the inspection hole 61. The thickness of the coating layer 63 can be set to 0.5 mm to 1.0 mm, for example.

  The first insulating portion 65 is disposed between the nut 60 and the lid member 12. The first insulating portion 65 includes a main body portion 65a disposed between the nut 60 and the lid member 12, and an extending portion 65b and an edge portion 65c formed integrally with the main body portion 65a. The first insulating portion 65 is in contact with the outer surface 12 b of the lid member 12, the communication hole 13 of the lid member 12, the terminal member 51, and the nut 60, and electrically insulates the lid member 12 and the terminal member 51. The first insulating portion 65 is made of a resin material such as polyphenylene sulfide, for example.

  The main body portion 65a is formed so as to surround the protruding portion 53, and is formed in an annular shape, for example. The inner peripheral surface of the main body portion 65 a is in contact with the outer peripheral surface 53 a of the protruding portion 53. The extending portion 65b extends downward from the central portion of the main body portion 65a. The extending part 65 b is formed in a cylindrical shape so as to surround the protruding part 53. The extending portion 65 b extends from the outside of the case 11 to the inside between the protruding portion 53 and the communication hole 13. The edge portion 65c protrudes from the outer peripheral portion of the main body portion 65a.

  The second insulating portion 67 is in contact with the inner surface 12 a and the facing portion 55 of the lid member 12 and electrically insulates the lid member 12 and the facing portion 55 of the terminal member 51. The second insulating portion 67 is made of a resin material such as polyphenylene sulfide.

  The sealing part 69 prevents the electrolyte filled in the case 11 from leaking out of the case 11. The sealing part 69 is an O-ring formed of a material having elasticity such as rubber, for example. The sealing portion 69 is disposed in a space surrounded by the inner surface 12 a of the lid member 12, the terminal member 51, and the second insulating portion 67.

  Next, the terminal structure of the negative electrode terminal 70 will be described. As shown in FIG. 5, the negative electrode terminal 70 includes a lid member 12, a terminal member 51, a nut 60, a first insulating portion 65, a second insulating portion 67, and a sealing portion 69. Yes. The terminal structure of the negative electrode terminal 70 is that the terminal member 51 is formed of a metal such as copper, and the terminal member 51 is electrically connected to the negative electrode 40 via the conductive member 44. It is the same composition except. Therefore, here, the same components are denoted by the same reference numerals, and description thereof is omitted.

  The battery module is assembled as follows. First, battery cells 10 as shown in FIG. 2 are prepared (in this embodiment, seven battery cells 10 are prepared), and a plurality of battery cells 10 are arranged in one direction. The battery cells 10 arranged in one direction are integrated by the restraint tool 3. Specifically, the plurality of battery cells 10 are sandwiched by a pair of end plates 3A, 3A from the juxtaposed direction, are arranged on the sides of the battery cells 10, and connect the pair of end plates 3A, 3A. A restraining load is applied by the connecting member 3B and the bolt 3C.

  Next, in a state where the bus bar 5 is placed on the upper surface 53 b of the terminal member 51, the bolt 6 is fastened to the fastening hole 53 c, whereby the bus bar 5 is fixed to the terminal member 51. In this way, the negative electrode terminal 70 of one battery cell 10 of the adjacent battery cells 10 and 10 and the positive electrode terminal 50 of the other battery cell 10 are connected by the bus bar 5, and the plurality of battery cells 10 are connected in series. Connected to become a power storage module. Then, the lead rod of the DC resistance meter is directly brought into contact with the terminal member 51 of the positive terminal 50 and the terminal member 51 of the negative terminal through the inspection hole 61, and the contact resistance between the positive terminal 50 and the negative terminal is measured. The

  In the battery module 1 of the above embodiment, the inspection hole 61 for accessing the outer peripheral surface 53 a of the terminal member 51 is formed in the nut 60 attached to the outer peripheral surface 53 a of the terminal member 51. That is, even when the battery cell 10 is assembled as the battery module 1, the access path to the terminal member 51 is ensured without removing the bus bar 5. Thus, the contact resistance between the positive electrode terminal 50 and the negative electrode terminal can be measured by directly bringing the lead rod of the DC resistance meter into contact with the terminal member 51 of the positive electrode terminal 50 and the terminal member 51 of the negative electrode terminal through the inspection hole 61. It becomes like this. For this reason, the measurement of the contact resistance between the terminal member 51 of the positive electrode terminal 50 and the terminal member 51 of the negative electrode terminal, which has been conventionally performed before the battery module 1 is assembled, can be omitted. Further, since the lead bar of the ohmmeter can be brought into direct contact with the terminal member 51 of the positive electrode terminal 50 and the terminal member 51 of the negative electrode terminal, not only an AC ohmmeter but also a DC ohmmeter can be used. As a result, workability and inspection accuracy when inspecting the contact resistance between the positive electrode terminal 50 and the negative electrode terminal 70 after the bus bar 5 is fastened can be improved.

  In the above embodiment, since the inspection hole 61 extends in a direction orthogonal to the direction in which the terminal member 51 extends, the ohmmeter lead rod inserted into the inspection hole 61 is brought into contact with the terminal member 51 in an orthogonal state. It becomes easy to let. Thereby, the inspection accuracy can be further improved.

  In the above embodiment, the coating layer 63 covered with the insulating material is formed on the inner peripheral surface of the inspection hole 61. Thereby, even if it is a case where the lead rod of an ohmmeter contacts the inner peripheral surface of the inspection hole 61, contact resistance can be measured with high precision.

  In the embodiment described above, the opening 61a of the inspection hole 61 formed in each of the plurality of battery cells 10 has the plurality of battery cells 10 arranged in one direction, the positive electrode terminal 50 and the negative electrode terminal 70 facing each other. All are arranged so as to be visible when viewed from the direction (first direction). Thereby, when inspecting the contact resistance between the positive electrode terminal 50 and the negative electrode terminal 70, the lead rod of the ohmmeter is not inserted into the inspection hole 61 from between the positive electrode terminal 50 and the negative electrode terminal 70, and the battery is always charged. A lead bar is inserted from the outer side of the cell 110 toward the inner side. As a result, the workability at the time of inspecting the contact resistance between the positive electrode terminal 50 and the negative electrode terminal 70 after the bus bar 5 is fastened can be further improved.

  Although one embodiment has been described above, the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the invention.

  In the above-described embodiment, an example in which one inspection hole 61 is formed in the nut 60 has been described. However, a plurality of inspection holes 61 may be formed. For example, when a hexagonal nut is employed as the fixing member, a configuration in which an opening 61a is formed on one of two continuous surfaces among the six side surfaces forming the outer shape of the hexagonal nut (a total of three inspection holes 61 are provided). Formed configuration). In this case, even if it is a case where the some inspection hole 61 is provided in a hex nut, the fall of the intensity | strength of a hex nut can be suppressed.

  With such a configuration, there are more options for the inspection hole 61 into which the lead bar of the ohmmeter is inserted. Therefore, when the battery cell 10 is assembled as the battery module 1, an event in which the lead bar cannot be inserted occurs. The probability of performing can be reduced. Even when the tightening is controlled by torque when the nut 60 is fastened to the terminal member 51, the opening 61a in the inspection hole 61 formed in one of the positive electrode terminal 50 and the negative electrode terminal 70 is the positive electrode terminal. There is a high possibility that the other side of 50 and the negative electrode terminal 70 is directed to the opposite side. As a result, the workability at the time of inspecting the contact resistance between the positive electrode terminal 50 and the negative electrode terminal 70 after the bus bar 5 is fastened can be further improved.

  In the said embodiment, although the inspection hole 61 gave and demonstrated the example extended so as to be orthogonal to the extension direction of the protrusion part 53 of the terminal member 51, it is not limited to this. For example, the inspection hole 61 may extend so as to intersect the extending direction of the protruding portion 53 of the terminal member 51 in an oblique direction. In the above embodiment, an example in which the opening 61 a is formed on the side surface that is a part of the surface forming the outer shape of the nut 60 has been described. 61a may be formed. Further, the opening 61a of the inspection hole 61 may face in any direction.

  In addition, for example, a wound electrode assembly may be used instead of the stacked electrode assembly 20. The wound-type electrode assembly is manufactured by winding a belt-like positive electrode, a belt-like negative electrode, and a belt-like separator around an axis in a stacked state.

  Examples of the power storage device include an electric double layer capacitor in addition to the battery cell 10.

  DESCRIPTION OF SYMBOLS 1 ... Battery module (electric storage module), 3 ... Restraint tool, 5 ... Bus bar, 6 ... Bolt, 10 ... Battery cell (electric storage apparatus), 11 ... Case, 12 ... Lid member (one side part of case), 13 ... Communication Hole: 20 ... Electrode assembly, 30 ... Positive electrode, 40 ... Negative electrode, 50 ... Positive electrode terminal, 51 ... Terminal member, 53 ... Projection, 60 ... Nut (fixing member), 61 ... Inspection hole, 61a ... Opening 63 ... Coating layer, 70 ... Negative electrode terminal.

Claims (9)

A terminal structure in a power storage device including a case for accommodating an electrode,
One side surface portion of the case having a communication hole that communicates the inside and the outside of the case;
A terminal member extending over the inside and outside of the case in the communication hole, and electrically connected to the electrode;
A fixing member attached to the outer peripheral surface of the terminal member outside the case, and fixing the terminal member to the one side surface part,
The fixing member has a terminal structure in which an inspection hole that communicates from an opening formed in a surface forming an outer shape of the fixing member to an outer peripheral surface of the terminal member is formed.   The terminal structure according to claim 1, wherein the inspection hole extends in a direction orthogonal to a direction in which the terminal member extends.   The terminal structure according to claim 1, wherein a plurality of the inspection holes are formed.   The terminal structure according to claim 1, wherein an inner peripheral surface of the inspection hole is covered with an insulating material. The fixing member is a nut;
The terminal structure according to any one of claims 1 to 4, wherein the nut is formed on an outer peripheral surface of the terminal member so as to be screwed into a screw groove. A case for accommodating a positive electrode and a negative electrode;
A positive electrode terminal and a negative electrode terminal having the terminal structure according to any one of claims 1 to 4,
A power storage device. When the direction in which the positive electrode terminal and the negative electrode terminal are opposite to each other and to the first direction,
The inspection hole extends along the first direction;
Wherein the opening in the inspection hole formed on one of the positive terminal and the negative electrode terminal, to the side of the other of the positive terminal and the negative electrode terminals are arranged is formed on the opposite side, according to claim 6 The power storage device described. A plurality of power storage devices, comprising: a case that accommodates a positive electrode and a negative electrode; and a positive electrode terminal and a negative electrode terminal that have the terminal structure according to claim 1;
The power storage module, wherein the terminal members of the plurality of power storage devices are electrically connected by a bus bar. When the direction in which the positive electrode terminal and the negative electrode terminal are opposite to each other and to the first direction,
The openings of the inspection holes formed in each of the plurality of power storage devices are all disposed so as to be visible when the plurality of power storage devices arranged in one direction are viewed from the first direction. Item 9. The power storage module according to Item 8.

Images